Superchargers have been used to enhance aircraft, automotive and marine engine performance for decades. With the passage of time, automotive and aircraft engine compartments have become increasingly crowded and complicated as improvements and accessories are added.
Representative supercharger/engine configurations are found in:
U.S. Pat. No. 5,392,751 to Taiji Matsubara where FIGS. 1 and 2 depict vividly the space limitations in a modern automotive engine compartment. Here, the supercharger is cradled between the cylinder banks of a V-type engine so as to avoid interference with other accessories, etc., in the engine compartment.
U.S. Pat. No. 5,224,459 to James Middlebrook teaches the configuration of a gear-driven, centrifugal supercharger.
U.S. Pat. No. 4,896,734 to Kenji Horiuchi et al teaches a supercharger automotive engine arrangement showing the complexity and lack of space in the modern automotive engine compartment. A direct gear drive is utilized.
U.S. Pat. No. 2,835,238 to J. W. Oehrli teaches a variable speed direct drive on a McCulloch (Paxton) supercharger and the complexity existing even in the 1950s.
U.S. Pat. No. 2,741,235 to W. A. Wiseman teaches the use of a simple, belt-driven, supercharger/aircraft engine system for installation prior to mounting the engine on an aircraft.
Problems unconnected with light aircraft, per se, virtually drove U.S. light aircraft manufacturers out of the private sector market. Early on, superchargers were useful in aircraft but were gear-driven. The supercharger/aircraft systems had many problems. The gear drives were unreliable and, as a result, aircraft turbocharging came to the fore. (See U.S. Pat. No. 2,835,238) Although the aircraft industry ended production of most of these early aircraft, they have proved to be quite airworthy when treated properly and are widely used today. In fact, the designs of recent craft follow the earlier models to a great extent.
However, users of these aircraft have needed to extend the service altitude at which the craft can be comfortably flown. For example, pilots wishing to fly in states with numerous mountain peaks with heights over 8-10,000 feet are always at risk. Additionally, pilots need increased altitude to reduce congestion of airways at lower altitudes. Finally, increased power availability during take-offs and landings provides an appreciable safety margin. Turbochargers and superchargers were slated to provide the additional power. However, turbochargers required extensive maintenance. On average, they must be rebuilt every 800-1000 hours and even when properly maintained, can shorten engine life and can damage the cylinders of the aircraft's engines. Therefore, the cost of equipment and maintenance has ensured that turbochargers have seen relatively little usage in light aircraft.
Unfortunately, the aircraft industry has not configured the engine compartment of lightweight aircraft to include superchargers. Further, so many problems arose out of the use of gear-driven superchargers and in light aircraft that they went out of use. As a result, the engine compartment or nacelle was not sized to house retrofitted superchargers and none are thought to be on the market even today.
Over time, competition in the United States essentially reduced the availability of light aircraft engines to two--the Continental and the Lycoming engines. The present invention provides a mechanism for retrofitting proven automotive superchargers into lightweight civilian aircraft using engines configured like the Lycoming or Continental engines. The installed superchargers effectively increase safe aircraft operation, i.e., performance is maintained at the 7500 foot level at altitudes of 7500-12,500 feet. Further, there is less engine stress at lower altitudes when a supercharger is used.
This invention provides kits for retrofit installation of superchargers on aircraft without modification of the engine cooling to improve aircraft performance after installation.